2011 Heartland Landmark Augusta. We had a no water situation last October as there was no hot or cold running water. Found out that the HWH outlet check valve (brass) had come apart. Took out all of the loose parts (O-ring and a white plastic plunger) and had HW after awhile. I ordered the new check valve from Heartland (now only plastic check valves available). I installed the new upper check valve and all works fine on CITY water connection. I put filtered water into the FW tank (2/3 full) and turned on the FW pump and no water is running in the system. I had replaced the FW pump (5.7 Smart....) with the recommended Shur Flow 4048 last summer and all worked fine until the HWH outlet check valve failed. I took out the new water pump and it pumped water out of a container of water +- 3 feet lower than the pump. I have not yet reinstalled the pump and am wondering if there are any thoughts that might solve the issue.